woking on wxptag issues...

git-svn-id: http://svn.wxwidgets.org/svn/wx/wxPython@73842 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
cleanup

git-svn-id: http://svn.wxwidgets.org/svn/wx/wxPython@73843 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add error check after creating an instance of the tag handler

git-svn-id: http://svn.wxwidgets.org/svn/wx/wxPython@73844 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add new cell types.
Let the backend know about the virtuals that may be overridden in the cell classes.

git-svn-id: http://svn.wxwidgets.org/svn/wx/wxPython@73845 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add a button handler to the sample.

git-svn-id: http://svn.wxwidgets.org/svn/wx/wxPython@73846 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix new location of old KeyEvent properties.

git-svn-id: http://svn.wxwidgets.org/svn/wx/wxPython@73847 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775